Remove variables that have been relocated to address space records.

Original variables are unused after relocations (given that
initializations of replacement variables are handled properly). The
original variables should be removed for clarity, even though the
OpenCL compiler can probably optimize them away. Furhermore, AMDs
compiler complains about unused variables and we don't want our code
to be rejected if the user chooses to use -Werror.

Signed-off-by: Rami Ylimäki <rami.ylimaki@vincit.fi>